I. Field of the Invention
The present invention pertains to fixed wireless telecommunications, and particularly to packet data transmission using a fixed cellular terminal (FCT).
II. Related Art and Other Considerations
Fixed wireless is the use of wireless technology to provide voice, data, or video service to fixed locations. There are several fixed wireless systems that can replace or bypass services that have traditionally been provided by copper wire or fiber cable. Wired systems that may be replaced or bypassed include wired telephone service, high speed telephone communication links, cable television systems, and local area network systems.
The basic fixed wireless technologies that are being introduced include wireless local loop (WLL), wireless cable, wireless bypass, and wireless local area networks (WLAN). These fixed wireless services can provide local dial tone voice service, high speed data, and video service. In some cases, a single fixed wireless system may provide all these services at the same time.
In one of its forms, wireless local loop (WLL) refers to distribution of telephone service, e.g., from the nearest telephone central office, over a wireless link to a fixed wireless terminal (FWT), also termed a fixed cellular terminal (FCT). One or more subscribers are connected to the fixed cellular terminal (FCT). Thus, such a wireless local loop system connects subscribers to the public switched telephone network (PSTN) using radio signals as a substitute for copper between, e.g., the fixed cellular terminal (FCT) and the switch.
Traditionally, the fixed cellular terminal (FCT) takes the form of a box with an antenna (or cable to an external antenna), power input, and connections for POTS phones, faxes, and data devices such as personal computers. The most basic service offered by wireless local loop (WLL) systems is to provide standard dial tone service known as plain old telephone service (POTS). Nowadays, in addition to the basic services, WLL systems typically offer advanced features such as high-speed data, residential area cordless service, and (in some cases) video services. More recently the sizes of such boxes have been reduced to about the size of a videocassette, including battery backup. The enclosures can be placed on a desktop or mounted on a wall. Ordinary telephone equipment, including POTS phones and Group III fax machines, can be connected via RJ-11 ports. Typically up to five devices can be connected in parallel (5 REN). When the subscriber picks up the phone, a dial tone is present and the telephone operates just as if it were connected to the landline PSTN.
Examples of fixed cellular terminals (FCT) are provided, e.g., in U.S. Pat. No. 5,991,641; U.S. Pat. No. 6,195,531; and U.S. Pat. No. 6,122,263; all of which are incorporated herein by reference.
Thus, fixed cellular terminals (FCT) provide PSTN-like services to all kinds of existing devices that can currently be connected to a normal fixed line. The fixed cellular terminal (FCT) can be connected to these devices by using a wired connection (e.g., two-wire connection, RS 232, etc.) or a wireless connection.
GSM (Global System for Mobile communications) is a European standard for a second generation wireless network which essentially serves as a wireless counterpart of the Integrated Services Digital Network (ISDN) system. GSM fixed cellular terminals provide an interface between a GSM radio and a fixed analog telephone line. Additional features, such as one or more digital data interfaces have been added. Examples of these digital data interfaces include RS232 and Bluetooth. Bluetooth is a universal radio interface operating within the ISM band. The Bluetooth standard is a low-cost short range wireless connection which uses much of the same range of frequencies for its frequency-hopping spread spectrum transmissions as the IEEE 802.11 standard (see www.bluetooth.com and Haartsen, Jaap, “Bluetooth—The Universal Radio Interface For Ad Hoc Wireless Connectivity”, Ericsson Review, No. 3, 1998).
In terms of data communications, single-timeslot or multi-timeslot GSM data channels were set up in the air interface. These data channels were implemented as circuit-switched data channels (CSD). These GSM data channels were connected either to the digital data interface or the analog line interface of the fixed cellular terminal. In the case of connection to the analog line interface, ITU-T V-series modulations were employed.
The advent of GPRS (General Packet Radio Services) ushered in a new feature to fixed cellular terminals: packet-switched communication over the digital data interfaces of the fixed cellular terminal. The digital data interfaces of the fixed cellular terminal are equally suitable for circuit-switched and packet-switched communications. Packet-switched communications have manifest advantages, including but not limited to efficiency and relatively low cost.
Despite the availability of the digital data interfaces for packet-switched communications, the most important interface provided by a fixed cellular terminal is the GSM radio/analog line interface. The GSM radio/analog line interface is utilized for speech, fax, and data communications. Indeed, the analog line is the most extensively used and more popular among users. Although the fixed cellular terminal is capable of using both circuit-switched (CSD, HSCSD) and packet-switched (GPRS) data, if the user wants to communicate over the analog interface of the fixed cellular terminal, heretofore only a circuit-switched connection could be established. Required utilization of a circuit-switched connection is unfortunate in due of the advantages of packet-switched communications.
In the above regard, the analog interface expects that a connection will be established by dialing a B-number to establish a circuit-switched connection with a B-party. But B-numbers and the like are not encompassed nor anticipated by most packet-switched protocols, such as TCP/IP, for example.
What is needed, therefore, and an object of the present invention, is utilization of a packet-switched service over a regular analog line modem connection of a fixed cellular terminal.